Interval TpTe Diagnostic Value in Diastolic Dysfunction of Patients with Hypertension

Introduction: Diastolic dysfunction has been shown to be associated with an increase in mortality rates in both normal and decreased systolic function. In patients with hypertension, there is elongation of transmural repolarization dispersion in left ventricular, which will cause heart diastolic relaxation disorders. The elongation of the transmural repolarization dispersion is indicated by the increase of the TpTe interval. We conducted this study to find out whether the TpTe interval had a good diagnostic value in detecting diastolic dysfunction in patients with hypertension. Methods: This is an analytic observational research using cross sectional design on hypertensive patients in whom echocardiography was performed. The study conducted in February 2017 until March 2017 in Dr. Sarjito general hospital Yogyakarta. Electrocardiography examination was taken after the patient was performed echocardiography. The TpTe interval was calculated using the ‘tail’ method at lead V5. Diastolic dysfunction was established using echocardiography with the ASE / EAE 2016 algorithm. Results: Of the 112 patients met the criteria of the study subjects. The cut-off value for TpTe was 103.97 m.s., based R.O.C curve analysis. TpTe interval ≥ 103.97 m.s. had a moderate diagnostic value for detecting diastolic dysfunction with 73% accuracy, 83% sensitivity, 64% specificity, 22% positive predictive value, and 97% negative predictive value. There were 66 (58.9%) subjects with TpTe interval <103.97 m.s. and 46 subjects (41.1%) with TpTe interval ≥103.97 m.s. There were 12 subjects (10.7%) with diastolic dysfunction. Bivariate and multivariate analyzes showed no demographic and clinical factors that independently affected the TpTe interval. Conclusion: The TpTe interval ≥ 103.97 m.s. had a moderate diagnostic value for detecting diastolic dysfunction in patients with hypertension.


INTRODUCTION
Diastolic dysfunction has been shown to correlate with an increase in mortality rates in both normal and decreased systolic function. 1 The current prevalence of diastolic dysfunction in studies conducted in the European population was 22.97% 2 and the prevalence of diastolic dysfunction in hypertensive patients was 43%. 3 In patients with hypertension changes in the Na + , K + and Ca 2+ ion channels in the left ventricle will result in increase of action potential duration (APD) as well as elongation transmural repolarization dispersion (TRD) left ventricle, which will lead to left ventricle diastolic relaxation disorders. 4,5 Currently there are several methods of electrocardiographic calculation that serves to know the TRD, such as T peak -T end interval (TpTe) and QT interval. The TpTe interval in electrocardiography depicts the left ventricular transmural repolarization dispersion that is associated with left ventricular relaxation mechanical dispersion in echocardiography. 6 Electrocardiography (ECG) which shows repolarization has been known to be associated with mechanical relaxation of left ventricle.
Research conducted by Alessandrini et al revealed that changes in ECG repolarization were associated with changes in echocardiography examination i.e, increased T-wave amplitude representing increase in ventricular filling rate peak, while QT interval increase was associated with increased IVRT. 7 The elongation of the TRD is represented by the increase of the TpTe interval, i.e. the time interval measured from the peak of the T wave to the end of the T wave. 8 Diagnosing diastolic dysfunction is important because electrocardiographic devices are an enormous tool in Indonesian primary health cares, but little research on ECG ability in diagnosing diastolic dysfunction. We are interested in conducting this study because we want to know the diagnostic value of TpTe interval with diastolic dysfunction in hypertension.

RESEARCH METHOD
This research is analytic observational research using cross sectional design. The

Characteristics of subjects
The study took place from January 2017

Analysis of diagnostic values of TpTe interval on diastolic function
To determine the diagnostic value of TpTe interval on diastolic function in hypertensive patients, the receiver operating characteristics (ROC) curve analysis was performed to obtain intersection point of TpTe interval with the optimum sensitivity and specificity. The sensitivity and specificity tests were then performed using 2x2 tabulation. The sensitivity and specificity tests were then performed using 2x2 tabulation.       Our study found that blood pressure and pulse rate at the time of ECG recording did not influence independently of the TpTe interval, in accord to a previous studyl. 6 Our study found that there was no significant difference in the age, sex and velocity variables in which this was consistent with the previous statements.
The TpTe interval was used as an indicator of repolarization heterogeneity because it has a consistent, independent predictive value of clinical outcome age, sex, and heart rate. 15,16 The study found that the majority of  the two groups. 17 The study explained that in patients with diabetes mellitus there will be disturbance of autonomous regulation and electrical inhomogeneity in the heart so that will cause increase of TpTe interval. 17  beta blockers and diuretics. 6 The drugs in this study did not affect the TpTe interval because the number of subjects using the drugs was few in number and the proportions did not differ significantly between the two groups.

LIMITATION
The limitation of this study is the small proportion of subjects with diastolic dysfunction, so it may not be able to accurately describe the condition of diastolic dysfunction in the population.